^^yup explained well
but its highly unlikely to get a password in months and even years if the digits are more than 8 and you cant guess a part of it.
it can also be used to break some encryption keys also...
But then all this will take a very long time unless you have a super computer
N yeah.. Getting the password through this method is just a dream if the person has a pd of more than 10 letters...
If a person has a password of 10 characters and the characters are alphabets(a-z, only small or capital) then you can try all the permutations possible.
Thats approximately 1.92x10^23
But since most mail services wont allow you to have a password with just small letters, the number of permutations will be much much higher..